Proportioning Valves and Balance Bars
A Proportioning Valve is installed in the rear brake line and allows you to adjust the rate of pressure rise to the back brakes. With an adjustable proportioning valve, you can slow down the pressure rise that occurs when you apply the brakes. Under braking, most vehicles transfer more weight to the front wheels. When this happens, the rear wheels lose some weight and can lock up if the pressure is too great too quickly in the braking process. Eventually full pressure is applied to the rear brakes through the proportioning valve.